// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2020 Western Digital Corporation or its affiliates. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define INSN_MATCH_LB 0x3 #define INSN_MASK_LB 0x707f #define INSN_MATCH_LH 0x1003 #define INSN_MASK_LH 0x707f #define INSN_MATCH_LW 0x2003 #define INSN_MASK_LW 0x707f #define INSN_MATCH_LD 0x3003 #define INSN_MASK_LD 0x707f #define INSN_MATCH_LBU 0x4003 #define INSN_MASK_LBU 0x707f #define INSN_MATCH_LHU 0x5003 #define INSN_MASK_LHU 0x707f #define INSN_MATCH_LWU 0x6003 #define INSN_MASK_LWU 0x707f #define INSN_MATCH_SB 0x23 #define INSN_MASK_SB 0x707f #define INSN_MATCH_SH 0x1023 #define INSN_MASK_SH 0x707f #define INSN_MATCH_SW 0x2023 #define INSN_MASK_SW 0x707f #define INSN_MATCH_SD 0x3023 #define INSN_MASK_SD 0x707f #define INSN_MATCH_FLW 0x2007 #define INSN_MASK_FLW 0x707f #define INSN_MATCH_FLD 0x3007 #define INSN_MASK_FLD 0x707f #define INSN_MATCH_FLQ 0x4007 #define INSN_MASK_FLQ 0x707f #define INSN_MATCH_FSW 0x2027 #define INSN_MASK_FSW 0x707f #define INSN_MATCH_FSD 0x3027 #define INSN_MASK_FSD 0x707f #define INSN_MATCH_FSQ 0x4027 #define INSN_MASK_FSQ 0x707f #define INSN_MATCH_C_LD 0x6000 #define INSN_MASK_C_LD 0xe003 #define INSN_MATCH_C_SD 0xe000 #define INSN_MASK_C_SD 0xe003 #define INSN_MATCH_C_LW 0x4000 #define INSN_MASK_C_LW 0xe003 #define INSN_MATCH_C_SW 0xc000 #define INSN_MASK_C_SW 0xe003 #define INSN_MATCH_C_LDSP 0x6002 #define INSN_MASK_C_LDSP 0xe003 #define INSN_MATCH_C_SDSP 0xe002 #define INSN_MASK_C_SDSP 0xe003 #define INSN_MATCH_C_LWSP 0x4002 #define INSN_MASK_C_LWSP 0xe003 #define INSN_MATCH_C_SWSP 0xc002 #define INSN_MASK_C_SWSP 0xe003 #define INSN_MATCH_C_FLD 0x2000 #define INSN_MASK_C_FLD 0xe003 #define INSN_MATCH_C_FLW 0x6000 #define INSN_MASK_C_FLW 0xe003 #define INSN_MATCH_C_FSD 0xa000 #define INSN_MASK_C_FSD 0xe003 #define INSN_MATCH_C_FSW 0xe000 #define INSN_MASK_C_FSW 0xe003 #define INSN_MATCH_C_FLDSP 0x2002 #define INSN_MASK_C_FLDSP 0xe003 #define INSN_MATCH_C_FSDSP 0xa002 #define INSN_MASK_C_FSDSP 0xe003 #define INSN_MATCH_C_FLWSP 0x6002 #define INSN_MASK_C_FLWSP 0xe003 #define INSN_MATCH_C_FSWSP 0xe002 #define INSN_MASK_C_FSWSP 0xe003 #define INSN_LEN(insn) ((((insn) & 0x3) < 0x3) ? 2 : 4) #if defined(CONFIG_64BIT) #define LOG_REGBYTES 3 #define XLEN 64 #else #define LOG_REGBYTES 2 #define XLEN 32 #endif #define REGBYTES (1 << LOG_REGBYTES) #define XLEN_MINUS_16 ((XLEN) - 16) #define SH_RD 7 #define SH_RS1 15 #define SH_RS2 20 #define SH_RS2C 2 #define RV_X(x, s, n) (((x) >> (s)) & ((1 << (n)) - 1)) #define RVC_LW_IMM(x) ((RV_X(x, 6, 1) << 2) | \ (RV_X(x, 10, 3) << 3) | \ (RV_X(x, 5, 1) << 6)) #define RVC_LD_IMM(x) ((RV_X(x, 10, 3) << 3) | \ (RV_X(x, 5, 2) << 6)) #define RVC_LWSP_IMM(x) ((RV_X(x, 4, 3) << 2) | \ (RV_X(x, 12, 1) << 5) | \ (RV_X(x, 2, 2) << 6)) #define RVC_LDSP_IMM(x) ((RV_X(x, 5, 2) << 3) | \ (RV_X(x, 12, 1) << 5) | \ (RV_X(x, 2, 3) << 6)) #define RVC_SWSP_IMM(x) ((RV_X(x, 9, 4) << 2) | \ (RV_X(x, 7, 2) << 6)) #define RVC_SDSP_IMM(x) ((RV_X(x, 10, 3) << 3) | \ (RV_X(x, 7, 3) << 6)) #define RVC_RS1S(insn) (8 + RV_X(insn, SH_RD, 3)) #define RVC_RS2S(insn) (8 + RV_X(insn, SH_RS2C, 3)) #define RVC_RS2(insn) RV_X(insn, SH_RS2C, 5) #define SHIFT_RIGHT(x, y) \ ((y) < 0 ? ((x) << -(y)) : ((x) >> (y))) #define REG_MASK \ ((1 << (5 + LOG_REGBYTES)) - (1 << LOG_REGBYTES)) #define REG_OFFSET(insn, pos) \ (SHIFT_RIGHT((insn), (pos) - LOG_REGBYTES) & REG_MASK) #define REG_PTR(insn, pos, regs) \ (ulong *)((ulong)(regs) + REG_OFFSET(insn, pos)) #define GET_RS1(insn, regs) (*REG_PTR(insn, SH_RS1, regs)) #define GET_RS2(insn, regs) (*REG_PTR(insn, SH_RS2, regs)) #define GET_RS1S(insn, regs) (*REG_PTR(RVC_RS1S(insn), 0, regs)) #define GET_RS2S(insn, regs) (*REG_PTR(RVC_RS2S(insn), 0, regs)) #define GET_RS2C(insn, regs) (*REG_PTR(insn, SH_RS2C, regs)) #define GET_SP(regs) (*REG_PTR(2, 0, regs)) #define SET_RD(insn, regs, val) (*REG_PTR(insn, SH_RD, regs) = (val)) #define IMM_I(insn) ((s32)(insn) >> 20) #define IMM_S(insn) (((s32)(insn) >> 25 << 5) | \ (s32)(((insn) >> 7) & 0x1f)) #define MASK_FUNCT3 0x7000 #define GET_PRECISION(insn) (((insn) >> 25) & 3) #define GET_RM(insn) (((insn) >> 12) & 7) #define PRECISION_S 0 #define PRECISION_D 1 #ifdef CONFIG_FPU #define FP_GET_RD(insn) (insn >> 7 & 0x1F) extern void put_f32_reg(unsigned long fp_reg, unsigned long value); static int set_f32_rd(unsigned long insn, struct pt_regs *regs, unsigned long val) { unsigned long fp_reg = FP_GET_RD(insn); put_f32_reg(fp_reg, val); regs->status |= SR_FS_DIRTY; return 0; } extern void put_f64_reg(unsigned long fp_reg, unsigned long value); static int set_f64_rd(unsigned long insn, struct pt_regs *regs, u64 val) { unsigned long fp_reg = FP_GET_RD(insn); unsigned long value; #if __riscv_xlen == 32 value = (unsigned long) &val; #else value = val; #endif put_f64_reg(fp_reg, value); regs->status |= SR_FS_DIRTY; return 0; } #if __riscv_xlen == 32 extern void get_f64_reg(unsigned long fp_reg, u64 *value); static u64 get_f64_rs(unsigned long insn, u8 fp_reg_offset, struct pt_regs *regs) { unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F; u64 val; get_f64_reg(fp_reg, &val); regs->status |= SR_FS_DIRTY; return val; } #else extern unsigned long get_f64_reg(unsigned long fp_reg); static unsigned long get_f64_rs(unsigned long insn, u8 fp_reg_offset, struct pt_regs *regs) { unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F; unsigned long val; val = get_f64_reg(fp_reg); regs->status |= SR_FS_DIRTY; return val; } #endif extern unsigned long get_f32_reg(unsigned long fp_reg); static unsigned long get_f32_rs(unsigned long insn, u8 fp_reg_offset, struct pt_regs *regs) { unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F; unsigned long val; val = get_f32_reg(fp_reg); regs->status |= SR_FS_DIRTY; return val; } #else /* CONFIG_FPU */ static void set_f32_rd(unsigned long insn, struct pt_regs *regs, unsigned long val) {} static void set_f64_rd(unsigned long insn, struct pt_regs *regs, u64 val) {} static unsigned long get_f64_rs(unsigned long insn, u8 fp_reg_offset, struct pt_regs *regs) { return 0; } static unsigned long get_f32_rs(unsigned long insn, u8 fp_reg_offset, struct pt_regs *regs) { return 0; } #endif #define GET_F64_RS2(insn, regs) (get_f64_rs(insn, 20, regs)) #define GET_F64_RS2C(insn, regs) (get_f64_rs(insn, 2, regs)) #define GET_F64_RS2S(insn, regs) (get_f64_rs(RVC_RS2S(insn), 0, regs)) #define GET_F32_RS2(insn, regs) (get_f32_rs(insn, 20, regs)) #define GET_F32_RS2C(insn, regs) (get_f32_rs(insn, 2, regs)) #define GET_F32_RS2S(insn, regs) (get_f32_rs(RVC_RS2S(insn), 0, regs)) #define __read_insn(regs, insn, insn_addr, type) \ ({ \ int __ret; \ \ if (user_mode(regs)) { \ __ret = __get_user(insn, (type __user *) insn_addr); \ } else { \ insn = *(type *)insn_addr; \ __ret = 0; \ } \ \ __ret; \ }) static inline int get_insn(struct pt_regs *regs, ulong epc, ulong *r_insn) { ulong insn = 0; if (epc & 0x2) { ulong tmp = 0; if (__read_insn(regs, insn, epc, u16)) return -EFAULT; /* __get_user() uses regular "lw" which sign extend the loaded * value make sure to clear higher order bits in case we "or" it * below with the upper 16 bits half. */ insn &= GENMASK(15, 0); if ((insn & __INSN_LENGTH_MASK) != __INSN_LENGTH_32) { *r_insn = insn; return 0; } epc += sizeof(u16); if (__read_insn(regs, tmp, epc, u16)) return -EFAULT; *r_insn = (tmp << 16) | insn; return 0; } else { if (__read_insn(regs, insn, epc, u32)) return -EFAULT; if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) { *r_insn = insn; return 0; } insn &= GENMASK(15, 0); *r_insn = insn; return 0; } } union reg_data { u8 data_bytes[8]; ulong data_ulong; u64 data_u64; }; /* sysctl hooks */ int unaligned_enabled __read_mostly = 1; /* Enabled by default */ #ifdef CONFIG_RISCV_VECTOR_MISALIGNED static int handle_vector_misaligned_load(struct pt_regs *regs) { unsigned long epc = regs->epc; unsigned long insn; if (get_insn(regs, epc, &insn)) return -1; /* Only return 0 when in check_vector_unaligned_access_emulated */ if (*this_cpu_ptr(&vector_misaligned_access) == RISCV_HWPROBE_MISALIGNED_VECTOR_UNKNOWN) { *this_cpu_ptr(&vector_misaligned_access) = RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED; regs->epc = epc + INSN_LEN(insn); return 0; } /* If vector instruction we don't emulate it yet */ regs->epc = epc; return -1; } #else static int handle_vector_misaligned_load(struct pt_regs *regs) { return -1; } #endif static int handle_scalar_misaligned_load(struct pt_regs *regs) { union reg_data val; unsigned long epc = regs->epc; unsigned long insn; unsigned long addr = regs->badaddr; int fp = 0, shift = 0, len = 0; perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr); #ifdef CONFIG_RISCV_PROBE_UNALIGNED_ACCESS *this_cpu_ptr(&misaligned_access_speed) = RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED; #endif if (!unaligned_enabled) return -1; if (user_mode(regs) && (current->thread.align_ctl & PR_UNALIGN_SIGBUS)) return -1; if (get_insn(regs, epc, &insn)) return -1; regs->epc = 0; if ((insn & INSN_MASK_LW) == INSN_MATCH_LW) { len = 4; shift = 8 * (sizeof(unsigned long) - len); #if defined(CONFIG_64BIT) } else if ((insn & INSN_MASK_LD) == INSN_MATCH_LD) { len = 8; shift = 8 * (sizeof(unsigned long) - len); } else if ((insn & INSN_MASK_LWU) == INSN_MATCH_LWU) { len = 4; #endif } else if ((insn & INSN_MASK_FLD) == INSN_MATCH_FLD) { fp = 1; len = 8; } else if ((insn & INSN_MASK_FLW) == INSN_MATCH_FLW) { fp = 1; len = 4; } else if ((insn & INSN_MASK_LH) == INSN_MATCH_LH) { len = 2; shift = 8 * (sizeof(unsigned long) - len); } else if ((insn & INSN_MASK_LHU) == INSN_MATCH_LHU) { len = 2; #if defined(CONFIG_64BIT) } else if ((insn & INSN_MASK_C_LD) == INSN_MATCH_C_LD) { len = 8; shift = 8 * (sizeof(unsigned long) - len); insn = RVC_RS2S(insn) << SH_RD; } else if ((insn & INSN_MASK_C_LDSP) == INSN_MATCH_C_LDSP && ((insn >> SH_RD) & 0x1f)) { len = 8; shift = 8 * (sizeof(unsigned long) - len); #endif } else if ((insn & INSN_MASK_C_LW) == INSN_MATCH_C_LW) { len = 4; shift = 8 * (sizeof(unsigned long) - len); insn = RVC_RS2S(insn) << SH_RD; } else if ((insn & INSN_MASK_C_LWSP) == INSN_MATCH_C_LWSP && ((insn >> SH_RD) & 0x1f)) { len = 4; shift = 8 * (sizeof(unsigned long) - len); } else if ((insn & INSN_MASK_C_FLD) == INSN_MATCH_C_FLD) { fp = 1; len = 8; insn = RVC_RS2S(insn) << SH_RD; } else if ((insn & INSN_MASK_C_FLDSP) == INSN_MATCH_C_FLDSP) { fp = 1; len = 8; #if defined(CONFIG_32BIT) } else if ((insn & INSN_MASK_C_FLW) == INSN_MATCH_C_FLW) { fp = 1; len = 4; insn = RVC_RS2S(insn) << SH_RD; } else if ((insn & INSN_MASK_C_FLWSP) == INSN_MATCH_C_FLWSP) { fp = 1; len = 4; #endif } else { regs->epc = epc; return -1; } if (!IS_ENABLED(CONFIG_FPU) && fp) return -EOPNOTSUPP; val.data_u64 = 0; if (user_mode(regs)) { if (copy_from_user(&val, (u8 __user *)addr, len)) return -1; } else { memcpy(&val, (u8 *)addr, len); } if (!fp) SET_RD(insn, regs, val.data_ulong << shift >> shift); else if (len == 8) set_f64_rd(insn, regs, val.data_u64); else set_f32_rd(insn, regs, val.data_ulong); regs->epc = epc + INSN_LEN(insn); return 0; } static int handle_scalar_misaligned_store(struct pt_regs *regs) { union reg_data val; unsigned long epc = regs->epc; unsigned long insn; unsigned long addr = regs->badaddr; int len = 0, fp = 0; perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr); if (!unaligned_enabled) return -1; if (user_mode(regs) && (current->thread.align_ctl & PR_UNALIGN_SIGBUS)) return -1; if (get_insn(regs, epc, &insn)) return -1; regs->epc = 0; val.data_ulong = GET_RS2(insn, regs); if ((insn & INSN_MASK_SW) == INSN_MATCH_SW) { len = 4; #if defined(CONFIG_64BIT) } else if ((insn & INSN_MASK_SD) == INSN_MATCH_SD) { len = 8; #endif } else if ((insn & INSN_MASK_FSD) == INSN_MATCH_FSD) { fp = 1; len = 8; val.data_u64 = GET_F64_RS2(insn, regs); } else if ((insn & INSN_MASK_FSW) == INSN_MATCH_FSW) { fp = 1; len = 4; val.data_ulong = GET_F32_RS2(insn, regs); } else if ((insn & INSN_MASK_SH) == INSN_MATCH_SH) { len = 2; #if defined(CONFIG_64BIT) } else if ((insn & INSN_MASK_C_SD) == INSN_MATCH_C_SD) { len = 8; val.data_ulong = GET_RS2S(insn, regs); } else if ((insn & INSN_MASK_C_SDSP) == INSN_MATCH_C_SDSP) { len = 8; val.data_ulong = GET_RS2C(insn, regs); #endif } else if ((insn & INSN_MASK_C_SW) == INSN_MATCH_C_SW) { len = 4; val.data_ulong = GET_RS2S(insn, regs); } else if ((insn & INSN_MASK_C_SWSP) == INSN_MATCH_C_SWSP) { len = 4; val.data_ulong = GET_RS2C(insn, regs); } else if ((insn & INSN_MASK_C_FSD) == INSN_MATCH_C_FSD) { fp = 1; len = 8; val.data_u64 = GET_F64_RS2S(insn, regs); } else if ((insn & INSN_MASK_C_FSDSP) == INSN_MATCH_C_FSDSP) { fp = 1; len = 8; val.data_u64 = GET_F64_RS2C(insn, regs); #if !defined(CONFIG_64BIT) } else if ((insn & INSN_MASK_C_FSW) == INSN_MATCH_C_FSW) { fp = 1; len = 4; val.data_ulong = GET_F32_RS2S(insn, regs); } else if ((insn & INSN_MASK_C_FSWSP) == INSN_MATCH_C_FSWSP) { fp = 1; len = 4; val.data_ulong = GET_F32_RS2C(insn, regs); #endif } else { regs->epc = epc; return -1; } if (!IS_ENABLED(CONFIG_FPU) && fp) return -EOPNOTSUPP; if (user_mode(regs)) { if (copy_to_user((u8 __user *)addr, &val, len)) return -1; } else { memcpy((u8 *)addr, &val, len); } regs->epc = epc + INSN_LEN(insn); return 0; } int handle_misaligned_load(struct pt_regs *regs) { unsigned long epc = regs->epc; unsigned long insn; if (IS_ENABLED(CONFIG_RISCV_VECTOR_MISALIGNED)) { if (get_insn(regs, epc, &insn)) return -1; if (insn_is_vector(insn)) return handle_vector_misaligned_load(regs); } if (IS_ENABLED(CONFIG_RISCV_SCALAR_MISALIGNED)) return handle_scalar_misaligned_load(regs); return -1; } int handle_misaligned_store(struct pt_regs *regs) { if (IS_ENABLED(CONFIG_RISCV_SCALAR_MISALIGNED)) return handle_scalar_misaligned_store(regs); return -1; } #ifdef CONFIG_RISCV_VECTOR_MISALIGNED void check_vector_unaligned_access_emulated(struct work_struct *work __always_unused) { long *mas_ptr = this_cpu_ptr(&vector_misaligned_access); unsigned long tmp_var; *mas_ptr = RISCV_HWPROBE_MISALIGNED_VECTOR_UNKNOWN; kernel_vector_begin(); /* * In pre-13.0.0 versions of GCC, vector registers cannot appear in * the clobber list. This inline asm clobbers v0, but since we do not * currently build the kernel with V enabled, the v0 clobber arg is not * needed (as the compiler will not emit vector code itself). If the kernel * is changed to build with V enabled, the clobber arg will need to be * added here. */ __asm__ __volatile__ ( ".balign 4\n\t" ".option push\n\t" ".option arch, +zve32x\n\t" " vsetivli zero, 1, e16, m1, ta, ma\n\t" // Vectors of 16b " vle16.v v0, (%[ptr])\n\t" // Load bytes ".option pop\n\t" : : [ptr] "r" ((u8 *)&tmp_var + 1)); kernel_vector_end(); } bool check_vector_unaligned_access_emulated_all_cpus(void) { int cpu; if (!has_vector()) { for_each_online_cpu(cpu) per_cpu(vector_misaligned_access, cpu) = RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED; return false; } schedule_on_each_cpu(check_vector_unaligned_access_emulated); for_each_online_cpu(cpu) if (per_cpu(vector_misaligned_access, cpu) == RISCV_HWPROBE_MISALIGNED_VECTOR_UNKNOWN) return false; return true; } #else bool check_vector_unaligned_access_emulated_all_cpus(void) { return false; } #endif #ifdef CONFIG_RISCV_SCALAR_MISALIGNED static bool unaligned_ctl __read_mostly; void check_unaligned_access_emulated(struct work_struct *work __always_unused) { int cpu = smp_processor_id(); long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu); unsigned long tmp_var, tmp_val; *mas_ptr = RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN; __asm__ __volatile__ ( " "REG_L" %[tmp], 1(%[ptr])\n" : [tmp] "=r" (tmp_val) : [ptr] "r" (&tmp_var) : "memory"); /* * If unaligned_ctl is already set, this means that we detected that all * CPUS uses emulated misaligned access at boot time. If that changed * when hotplugging the new cpu, this is something we don't handle. */ if (unlikely(unaligned_ctl && (*mas_ptr != RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED))) { pr_crit("CPU misaligned accesses non homogeneous (expected all emulated)\n"); while (true) cpu_relax(); } } bool check_unaligned_access_emulated_all_cpus(void) { int cpu; /* * We can only support PR_UNALIGN controls if all CPUs have misaligned * accesses emulated since tasks requesting such control can run on any * CPU. */ schedule_on_each_cpu(check_unaligned_access_emulated); for_each_online_cpu(cpu) if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED) return false; unaligned_ctl = true; return true; } bool unaligned_ctl_available(void) { return unaligned_ctl; } #else bool check_unaligned_access_emulated_all_cpus(void) { return false; } #endif